Yarb

Thanks for taking the time to help and educate my friend.

I agree, Cleaning with a brass brush will not get the job done. Clean the oil off. Sandpaper all the electrodes and you have a chance.

There are open air side vent actuators under the dash just above the side kick panels

Seriously, It could be a mud dauber. In Florida they’re terrible and that’s what I sounds like. If that’s the case they don’t live that long. How long have you heard it?

Spraythem down with carburetor spray as well

IMO fix the spark issue first. Way to many variables here.

@SteveJcould probably give a better answer but it’s current limiting and possibly a voltage drop.

@siteunseenTime to hit the library!!!

The electrical spark issue is what you need to be concentrating on right now.

Agreed, They didn’t design it for production without a reason.

Might want to reach out to “ZTherapy” and ask what their base line settings were when they rebuilt your carburetors. You have the paperwork and I’m sure they would be happy to guide you through the process. Over time a lot of hands have been on the carbs themselves. Maybe it’s time to start from scratch with their direction. My two cents

On finding one I hope I didn’t imply that it was easy but they are out there. Personally I look for the permanent fix in order to move on to the next project. It all comes down to the end result you are looking for. Everyone has a budget which I fully understand.

Wish I could find that in my hometown.

For the trouble and pain it is to change out. Do yourself a big favor and replace it with a N42. What was the goal of sending it to the shop. Just EGR removal? If that’s it you are much better off getting a N42. These engines are fun to find vacuum leaks anyway. No doubt I’d change it out. I’m sure you can find something reasonable here on the forum. IMO of course.

N42 Intake!! Call it a day.

Non-EGR intake.

Try to find I believe a N42 manifold from a 75 model Z.

Not sure if it needs to be said but turn them gently.

Sure looks like it.

Buy a can of carburetor spray. Some 400 grit sand paper and clean them up. Doesn’t take that long to do. Slow down and be patient. You are not there yet but you Have to be Patient. Finally making positive steps. Still a long way to go. This won’t be fixed in a days time. Step by step friend.

Being so far away and according to how much you are committed to this car I would consider it very seriously. IMO of course.

That one piece of trigger wheel broken off is going to make a difference. You are missing a pulse being sent to the ignition module.

Shipping would be insane but definitely something to consider. What a great spare to have around.

Don’t think you’re going to get a clear picture until you clean those up or replace them. I assume these are the same plugs that were in there before the change was made. One variable at at a time. Otherwise you won’t have a clear idea of what’s happening. IMO

Hang on…Wait until @gundeegets back to you. Slow down friend.